BEIJING - Afghanistan's foreign minister has called for China to open up their common border as an alternative supply route to help forces battling Islamic militants, Chinese state media said Thursday.

Rangin Dadfar Spanta, who is on a four-day visit to China, made the call in a speech on Wednesday at a Chinese think tank, the China Daily newspaper said.

"The solution must be comprehensive, regional and international," Spanta said, adding his "personal wish, which is opening the Wakhan Corridor between Afghanistan and China."

The corridor is a narrow strip of Afghan territory, the eastern end of which leads to a mountainous 76-kilometre (47-mile) border with China.

The idea of using the thin strip of land as a potential alternative route for supplying US and NATO forces battling Muslim extremist groups such as the Taliban in Afghanistan's rugged terrain has been floated before.

However, the paper quoted Chinese experts as saying the call was likely to fall on deaf ears in China, which fiercely resists any moves viewed as compromising its national sovereignty.

China also says it faces a severe threat from Islamist separatists in its Muslim western regions and tightly controls its borders there.